Skew rolling of solid ingots

ABSTRACT

Skew rolling mill for piercing solid ingots having a stand with a center line and a mandrel on that line on one side of the stand, and pushing means on the other side of the stand, mounted for turning on an axis and for pivoting transverse thereto, the pushing means mounted on a cross bar; first and second drum means driven in unison and disposed respectively on both sides of the center line, on said other, the feeder side of the stand, the drum means having pitch circle that is tangent to a plane that runs through the center line; chains on the drum means and connected to the cross bar for displacing the cross bar and the pushing means on the center line.

United States Patent [191 Pfeiffer et a1.

SKEW ROLLING OF SOLE HNGOTS Inventors: Gerd Pfeiffer; Hans-Peter Kran, both of Mulheim/Ruhr; Wilhelm Feldmann, Duisburg, all of Germany Mannesmann Aktiengesellschatt, Dusseldorf, Germany Filed: Aug. 26, 1971 Appl. No.: 175,361

Assignee:

Foreign Application Priority Data Sept. 3, 1970 Germany 7033450[U] US. Cl. 72/97, 72/250 Int. Cl 1321b 19/04 Field of Search.... 72/97, 209, 250, 95, 96, 428

References Cited UNITED STATES PATENTS 5/1923 Becker 72/97 6/1935 Moise 72/97 5/1939 Anater 72/97 8/1885 Hunt et a1..; 72/250 4/1910 Peters 72/209 Feb. 12, 1974 3,656,331 4/1972 Kuypers et a1 72/97 389,585 9/1888 Mannesmann 72/97 1,882,655 10/1932 Clark 72/96 2,958,244 11/1960 Rodder 72/97 3,407,638 10/1968 Greis et a1. 72/96 Primary Examiner-Lowell A. Larson Attorney, Agent, or Firm-Smyth, Roston & Pavitt 57 ABSTRACT Skew rolling mill for piercing solid ingots having a stand with a center line and a mandrel on that line on one side of the stand, and pushing means on the other side of the stand, mounted for turning on an axis and for pivoting transverse thereto, the pushing means mounted on a cross bar; first and second drum means driven in unison and disposed respectively .on both sides of the center line, on said other, the feeder side of the stand, the drum means having pitch circle that is tangent to a plane that runs through the center line; chains on the drum means and connected to the cross bar for displacing the cross bar and the pushing means on the center line.

2 Claims, 2 Drawing Figures v. 1 SKEW ROLLING OF SOLID INGOTS The present invention relates to a skew rolling mill for piercing solid ingots such as round bars. Usually, such mills include drive spindles or shafts for the rolls and a mandrel rod on a thrust block. Moreover, a plunger or ram is provided to push the ingot into the mill, the plunger beingoperated by rod linkage or by piston and cylinder control or the like. The invention relates particularly to replacement of the conventional ingot pusher by a device forcing the ingot into the mill during piercing. The known devices are not suitable for this purpose as they are unable to exert significant pressure upon the ingot.

Skew rolling mills and those with conical rolls are known for expanding hollow ingots using means for spinning the hollow ingot during expanding. These means for spinning include a cross bar bearing against a support and being movable under power. A tool head is mounted on the cross bar that can be turned on an axis and can be pivoted in every direction transverse to that axis. Hydraulic means or threaded spindles are used for displacing the rod. It should be emphasized that these expanding mills differ from piercing mills in principle and in construction, and the components used in one are not necessarily useable in the other, particularly as far as spinning tools are concerned.

Upon developing piercing mills, it has been recognized that the displacement drive for the pusher has detrimental effects on operability and economy of the mill. A hydraulic displacement drive with piston and cylinder has to be placed in front of the pusher and increases the total length of the mill accordingly. Therefor, the commonly used roll drive spindles must be enlarged, and the drive has to be placed in a different position. On the other hand, were one to place the piston and cylinder between the roll stand and the pusher rod, the overall width dimension of the stand has to be increased and that, in turn, impedes ingot feeding. Utilization of threadedspindles introduces the added disadvantage that fast longitudinal displacements are not feasible, particularly for retracting the pusher after a pass, but speed is desirable after rolling to avoid delay of feeding the next ingot for the next pass.

It is an object of the present invention to improve skew rolling mills for piercing solid ingots using a thrust supported mandrel as well as a pusher whereby it is a particular object of the invention to use a cross bar that is both, displaceable under power but bears against a support, and supports a head with pusher that turns on an axis and is pivotable in every direction transverse to the axis, such as is known for expanding mills.

In accordance with the preferred embodiment of the invention, it is suggested to connect the cross bar to an elongated transmission element that can be wound on drums such as chains. The drums that are provided for this purpose, are placed only slightly apart from the mill stand and to both sides of the center line of rolling and in between the drive spindles. The pitch circles of the drums are to be tangent to a. plane through the center of rolling, and the drums are driven in unison.

In the preferred form of practicing the invention, the elongated elements are to. be chains, the drums being chain or sprocket wheels accordingly; Utilization of chains or the like that can be reeled, permits reduction of the overall dimension of the mill, particularly as compared with the several drives outlined above. Significantly then, already existing rolling mills can be improved in accordance with the teaching of this invention. Neither, the pivot range of the rolls, nor ingot feeding is detrimentally influenced by such supplementing equipment.

Upon using such flexible transmission elements, oscillatory and other irregular motions of the ingot are not transmitted upon the pusher drive and that, in turn, provides for simpler and sturdier bearing support of the head. This advantageous feature actually makes it possible at all to mount such a head so it can transmit forces upon the ingot which are proportioned so as to effectively control the piercing process. Chains have quite a small cross section so that they can be connected to the cross bar as well as to the reeling drums in a plane that runs through the rolling center, and consequently, pitching moments of the cross bar are sub stantially avoided.

While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention, it is believed that the invention, the objects and features of the invention and further objects, features and advantages thereof will be better understood from the following description taken in connection with the'accompanying drawings in which:

FIG. 1 is a top elevation of a displacement drive for the pusher in a rolling mill in accordance with the preferred embodiment of the invention; and

FIG. 2 is a cross section view through that drive along lines IIII in FIG. 1.

Proceeding now to the detailed description of the drawings, reference numeral 1 denotes the rolling stand for the rolls which are driven by a motor (not shown) via gearing 4 and drive and steering spindles 2 and 3. The delivery end of the mill is to the right of stand 1, and there is provided a thrust supported mandrel for ingot piercing as is known per se for piercing mills. The mandrel with rod and support is not shown and is conventional.

The rolling mill is illustrated with a round bar ingot 5 in the feeder path, to the left of the stand. The ingot sits on support elements 7 in a trough like configuration 6. Ingots are fed into the particular immediate feeder path from above and laterally as indicated by arrows 8.

The immediate feeder path is, of course, on the center line 9 of rolling. Two chains or sprocket wheels 10 and 1 l are mounted on a common shaft 12; the wheels are disposed respectively on both sides of center line 9 and in between the drive elements 2 and 3. Shaft 12 extends transversely to center line 9 and is driven by a motor 13. Chains l4 and 15 loop around sprocket wheels 10 and 11 for driving them respectively upon turning by operation of motor 13.

A cross bar 16 is provided and connected to the two chains, also on both sides of the center line. The upper stringers of the two chains 14 and 15 are disposed in a horizontal plane that includes center line 9 of rolling, which also coincides with the center axis of ingot 5 in the feeding position. Accordingly, the pitch circle of wheels 10 and 11 are tangent to that plane.

The cross bar 16 serves as mount for a head 17 permitting turning of the head on an axis that coincides also with center line 9. Additionally, the ball-andsocket like support and configuration of head 17 in cross bar 16 permits pivoting of the head on any axis directions transverse to the axis of rotation of the head as defined. A pushing rod 19 is mounted on head 17 and engages ingot 5, thereby spanning the distance between head and ingot, and more particularly, the rod 19 spans the distance between the most advanced position of cross bar 16 and the rolling plane. Cross bar 16 bears against support rails 20 and 21.

Upon driving the chains 14 and 15 in proper direction, i.e., upon pulling the upper stringers of the chains, cross bar 16 is pulled towards the mill, whereby pusher rod 19 is forced against the ingot. Accordingly, the ingot moves into the rolling gap against the mandrel. That application of force upon the ingot persists during rolling and may be subject to control through torque control of motor 13.

The chains 14 and 15 may have actually endless configuration, the lower portion leads underneath cross bar 16. Idler wheels or drums 22 and 23 complete the reeling paths. Upon reversing drive 13, the chains pull on cross bar 16 from the other side to return the cross bar with head and pusher to the initial position. That return can be carried out quite rapidly as comparatively little torque is needed.

The invention is not limited to the embodiments described above but all changes and modifications thereof not constituting departures from the spirit and scope of the invention are intended to be included.

We claim:

1. In a skew rolling mill for piercing solid ingots having a stand with a center line and a mandrel on that line and disposed on one side of the stand, and pushing means disposed on the other side of the stand, the improvement comprising in combination:

a cross bar disposed for mounting one end of the pushing means, (a) for rotation on said center line as an axis, and (b) for pivoting transverse to said axis in said cross bar, the pushing means extending on that axis with its other end towards the ingot and the mandrel;

first and second drum means disposed respectively on both sides of the center line, and on said other, the feeder side of the stand, the drum means having pitch circle that is tangent to a plane that runs through the center line;

elongated means for winding onto and for power transmission by the drum means and connected to the cross bar for displacing the cross bar and the pushing means on and along the center line; and

means for driving the drum means in unison to obtain displacement of the cross bar for the pushing means to push an ingot into the stand and towards the mandrel.

2. The improvement as in claim 1, the elongated 7 means being chains, the drums being chain wheels,

sprocket wheels or the like. 

1. In a skew rolling mill for piercing solid ingots having a stand with a center line and a mandrel on that line and disposed on one side of the stand, and pushing means disposed on the other side of the stand, the improvement comprising in combination: a cross bar disposed for mounting one end of the pushing means, (a) for rotation on said center line as an axis, and (b) for pivoting transverse to said axis in said cross bar, the pushing means extending on that axis with its other end towards the ingot and the mandrel; first and second drum means disposed respectively on both sides of the center line, and on said other, the feeder side of the stand, the drum means having pitch circle that is tangent to a plane that runs through the center line; elongated means for winding onto and for power transmission by the drum means and connected to the cross bar for displacing the cross bar and the pushing means on and along the center line; and means for driving the drum means in unison to obtain displacement of the cross bar for the pushing means to push an ingot into the stand and towards the mandrel.
 2. The improvement as in claim 1, the elongated means being chains, the drums being chain wheels, sprocket wheels or the like. 